dict = {'name':'Runoob','Age':7,'Class':'First'}

# 查询
print(dict['name'])
print(dict['Age'])

#修改字典
dict['Age'] = 8
dict['School'] = '菜鸟教程'
print(dict)

# 删除字典
del dict['Class']
# dict.clear() 清空字典
# del dict() 删除字典

# 字典内置函数
# len(dict) 计算字典元素个数，即键的总数
print(len(dict))